The present invention relates to a safety and regulation valve unit for a gas installation, particularly a heating installation, comprising a duct through which the fuel can flow between an inlet and at least one outlet, on-off fuel-valve means interposed in the duct between the inlet and the at least one outlet, a movable device for controlling the on-off valve means, as well as actuator means acting on the movable device in order to move it towards a first operative position in which it cooperates with the on-off valve means in order to put the inlet into communication with the at least one outlet.
Valve units of the known type indicated above are normally operable manually or by means of electromagnetic control devices. In particular, in units operable by means of electromagnetic devices, the movement of the movable device can be controlled automatically. However, this control is achieved with the use of fairly complex electronic systems which generally operate by regulating the supply voltage of the control device. Moreover, with these systems fairly low forces and small movements of the movable device are achieved.